Automatic copying lathe for shoe lasts



Now. 28, 1950 E. TOFHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS 9Sheets-Sheet 1 Filed March 16, 1946 m/en fors Lauren 0 e E. Tqoham CZae, LKnott Npv. 28, 1950 E. TOPHAM ET AL 2,531,590

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 Sheets-Sheet2 2% 521/612 fors LaurenceE 7bphczm 8 Cl de LKnatt Nov. 28, 1950 L. E.TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 19469 Sheets-Sheet 3 fiwenfmzs Lauren a a E 75,0ham

1950 E. ToPi-iAM ET AL 2,531,590

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 9Sheets-Sheet 4 clur'cnoe E. Epham Clyde LKnott Nov. 28, 1950 E. TOPHAMET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS 9 shee s-sheet 5 FiledMarch 16, 1946 hum-furs Lau P621663 E 7'0pham Clyde L. K1702! Aft L. E.TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS I Filed March 16,1946 9 Sheets-Sheet 6 Filed March 16, 1946 9 Sheets-Sheet 7 Nov. 28,1950 E. TOPHAM ET AL 5 5 AUTOMATIC COPYING LATHE FOR SHOE LASTS[In/611mm Laurqae' 76p ha m Kim; 1

Nov. 28, 1950 L. E. TOPHAM ET AL AUTOMATIC COPYING LATHE FOR SHOE LASTS9 Sheets-Sheet 8 Filed March 16, 1946 fizz/6:21am Lau r'enceE 75phamOZyeL/fnotz T A AE w v .wwy 1 1 9 v u m M w i H J v z w m 7 1 w W 6 9 MHH H. W. 1 1 H .-i--- v M v: 2 mm m F. 7 m 9 W 9 @V. 28, mm E. TOPHAM ETAL 2,531,59U

AUTOMATIC COPYING LATHE FOR SHOE LASTS Filed March 16, 1946 9Sheets-Sheet 9 [vi/672mm Laurence E. 75 19/2071:

fact that their speeds are not constant.

Patented Nov. 28, 195@ UNITED S GFFKCE AUTOMLATIC CQPYING LATHE FOR SHOELASTS Application March 1S, 1946, Serial No. 654,924

13 Claims. I

This invention relates to copying lathes, and its purpose is to'provideautomatic means for varying the angular turning speed of a lathe inaccordance with radial dimensions and surface characteristics of theform to be copied. These dimensions and characteristics, when utilizedas herein set forth, will permit relatively rapid turning speed underthe more favorable turning conditions, and will retard the speed onlywhen less favorable conditions require retardation, and

thereby insure a corresponding increase in the productive capacity of alathe consistent with accuracy of the products.

As herein illustrated, the speed-regulating equipment provides threeautomatic controls derived from a pair of mated models and twoindividually movable swing frames in which the models are mounted. Oneof the swing frames is hereinafter termed the master swing frame becauseits motions determine the shape of the product. Whichever model ismounted in the master swing frame becomes the master model, while themate thereof serves as a pilot model in the other swing frame which istermed pilot swing frame. The two models are interconnected to rotate atequal speeds despite the Moreover, the face plates or chucks for drivingthem are out of angular phase, their phase differential being anarbitrary quantity, preferably about 1%", and the pilot model beingahead of the master model in that respect.

A variable-speed driving unit is provided to rotate the models and thework block, and its driving speed is governed by a regulator themovements of which are responsive to the three automatic controlshereinbefore mentioned. One of these controls, termed radius control,derives its speed-regulating movements solely from the pilot swingframe, and its effect is to vary the speed of the driving unit inverselyaccording to the distance between the pilot modelwheel and the turningaxis of the pilot model. The lengths of the several radii of the pilotmodel are the essential factors that enable this control to regulate theangular turning speed of the models and the work-bloclr.

One of the other automatic controls above mentioned can be utilized tovary the turning speed of the models according to the steepness ofacclivities and declivities in their contours, and when so utilized itwill prevent excessive velocity of the swing frames that would otherwiseoccur if full advantage is to be taken of the more favorable operatingconditions to increase the turning speed. This automatic control ishere- 2 inafter termed sustaining modifier because its speed-regulatingeffect is sustained in accordance with the angular extent of theacclivities and declivities of the models.

The third automatic control is hereinafter termed transitory modifierbecause it can be utilized to modify the turning speed with a transitoryeffect. Its purpose is to prevent sudden acceleration of the masterswing frame in response to the more abrupt deviations in the contour ofthe master model. The desired effect is obtained by utilizing the moreabrupt deviations in the pilot model, which come into play earlier thanthose of the master model, to produce transitory components of speedreduction before the corresponding deviations in the master model cometo the master model-Wheel, and to eliminate such transitory componentsgradually as soon as they reach their peak. In this respect, the pilotswing frame detects, in advance, the needs of the master swing frame andactivates the transitory modifier accordingly.

The components of speed-regulation derived from the several controls,whether increments or decrements, are communicated to three separateinput points of an integrator in triangular relation to each other.Another point of the integrator, constituting the output point thereof,is connected to the speed regulator which is thereby rendered responsiveto any one, any two, or all three of the automatic controls.

The novel features of the present invention are illustrated as appliedto a copying lathe of the type setforth in United States Letters PatentNo. 2,072,228, granted March 2, 1937, on an application filed in ournames, but this difference is to be observed, namely, the patented latheincludes only one swing frame, while the present invention utilizes asupplemental swing frame for the pilot model in addition to a masterswing frame for the master model and the work-block. The former latheand that herein illustrated have identically the same provisions forgirthgrading and length-grading, with this exception: the model-wheelcarriage of the instant lathe is provided with two model wheels, one forthe master model and the other for the pilot model, and they areinterconnected by means arranged to impart girth-grading movements tothe pilot model wheel commensurate with those of the ,master modelwheel.

to effect variations in turning speed as promptly as required to satisfythe purpose of the present invention. Because of this consideration theinstant lathe is driven by a hydrodynamic variablespeed unit of a wellknown commercial type that operates with relatively slow angularvelocity and with positive effect not only to accelerate but also todecelerate its rotational output. It includes a rotary pump the rotor ofwhich may be driven at a constant speed by an electric motor, and thestator of which may be shifted to and fro to regulate its hydraulicoutput. The hydrodynamic unit illustrated herein is of the type setforth in United States Letters Patent No. 2,074,068, granted March 16,1937, and the means for regulating the speed of its rotational output isof the type set forth in United'States Letters Patent No. 2,105,454,granted January 11, 1938. The applicant of both of these patents isWalter Ferris.

Of the drawings,

"Fig. 1 is an elevation of the left-hand'end of'a lathe embodying theinvention,'porti'ons of the swing frames being broken away and bothmodels being represented in'section;

Fig. 2 is a top plan View of the lathe. For a topplan view of themodels, a work-block, etc.

seeFig. 15;

Fig. 3 is a phantom elevation correspondin to "Fig. 1 but illustratingthe transmission means for rotating the models and the work-block;

Fig. 3a is a sectional elevation of transmission gearing for driving thescrew-shaft'that feeds the cutter-carriage and the model-wheel car-'riage;

Fig.4 is a top plan including elements of the transmission means, themodel-wheel carriage,

and some of the elements'for'regulating' the turning speed;

Fig. 5 is a sectional elevation of an assemblage of elements of themodel-wheel carriage and the master swing frame;

Fig. 6 is an end elevation of an assemblage of elements of thegirth-grading mechanism left out'of Fig. 5 foreground;

Fig. "7-is an end elevation, partly in section (line VII-VII of Fig. 8),of theassemblage'represented in'Fig. 6;

Fig. 8 is a plan section indicated by line VIII-VIII in- Fig. 6

Fig. 9 is'a vertical section (line IX I-Xin'Fig. 11) of a modifier forregulating the speed of the lathe according to the steepness of thesurfaces of both models;

Fig. 1 0 is a plan section (line X X*in'Fig.' 9)

"of a linkage by which both modifiers (Figs. 9 --and12)-are operatedwith motions derived from the differential member (Fig. 14)

'Fig. 11 is an end elevation, partly in section,

Fig. 11a is a top plan view of the integrator which has three inputpoints of motion and one output point for operating the speed regulator;Fig. '12 is a front elevation, partly in section, of the assemblagerepresented in Fig. 11 and some additional elements included in Figs. 1and 4 (see line XIIXII in Fig. 11)

Fig. 13 is a schematic view in end elevation, as in Fig. 1, of anassemblage including the swing frames, the models, and a linkage of theradius control;

Fig. 14' is an end elevation of an assemblage including the speedregulator,thethree-point integrator and a diiferential member by whichboth modifiers are operated according to swing frame differentials;

Fig. 15 is a top plan view including both models and a work-block, faceplates for supporting their butt ends and driving them, and tailstocksfor supporting their toe ends; and

Fig. 16 represents a cross-sectional contour of the pilot model.

Since many of the details of construction and features of organizationherein illustrated are the same as, or similar to, corresponding detailsand features shown and described in our earlier development (UnitedStates Patent No. 2,072,228) above mentioned, the present descriptionwill be abbreviated with respect to them. It is to be understood,nevertheless, that the present invention is applicable to lathes capableof turning a complete last in one piece instead of the type selected,which is designed to turn foreparts and heel parts individually.

Fig. 2 includes a cutter-carriage Ill and a model-wheel carriage ll bothslidable on guide rails l2 and 63 provided by the main frame f4, anelectric motor [5 mounted on the carriage I0, a rotary-cutter head l6carried by the'shaftof the motor, a screw-shaft'l'i' having a left-handthread for feeding the carriage l0 and a righthand thread for feedingthecarriage ll,an'd;a long swing frame t8 in which two face plates is and2B and two tail stock centersZl and '22 are arranged on a common turningaxis. 'The face plates are both afiixed to a driven spindle '23 and eachis provided with crossed'ribs or keys (Fig. 15), those of the plate 19tobe'n'ested in intersecting grooves 24 in the butt end of a work-block25, and those of the plate Zil'to be nested in similar grooves 26 in thebutt end of a model 21. These elements are separated in this View merelyto show clearly their interlocking formations. A small socket 28isformed in the toe end "of the block 25 to receivethe center 21, and acorresponding socket 253 is in the toe end of the model to receive thecenter 22.

One of the novel features of the lathe is an auxiliary swing frame 30located at the rear of the'main frame M opposite the model-carryingsection of the swing frame 18. For descriptive and identifying purposesthe swing frame |8 is hereinafter termed master swing frame and theswing frame 3i] is termed pilot swing. frame." The latter is shorter andmuch less heavythan the master swing frame, and itsload is .less heavythan that carried by the master .swing frame. The only load to becarried by the pilot swing frame is a pilot model 3!, which is the mateof the master model 21. Since the inertia factor of the pilot swingframe (including load) is very much less than that of the. master swingframe, it has appreciably lesstendency tocause overtravel during periodsof outswing, and requires less power to reverse its directionof travel.

The pilot swing frame carries a tail-stock center 32 and a face plate 34for supporting and 1:0- tating the pilot model. This face plate is.aduplicate of the face plate 28 and is affixed to. aldriven spindle 33.

The master swing frame I8 includesahorizontal rock-shaft 35 (Figs. 4 and8) and an extension member l-til afiixed thereto and supportedbyatrunnion 88 fastened inthe main frame Hi. When a model is set up inthis swing frame it is held against a model-wheel 36 bythe. force of aspring 31 connected to-anarm.of--the swing frame (see upper end of Fig.2). The pilot swing frame to likewise includes a rock-shaft 38 journaledin bearings in the main frame ii. A model set up therein is held againsta model-wheel 39 by the force of a spring it] (Figs. 1 and 2) connectedto an arm of this swing frame.

Although both model-wheels are mounted o the carriage ll they aremovable toward and from each other for girth-grading, and for thispurpose the carriage is provided with parallel bearings for two siidablerack-bars ii, 52 (Figs. i and 5) both intermeshed with an interposedpinion $3. The latter turns on a pivot affixed to the carriage andinsures equal but opposed endwise movements of the rack-bars. Eachrackbar carries a boss id rigidly related thereto. A pivot pin :15connects an arm it and one boss 4 3, while a similar pin connects an armll and the other boss. The model-wheels 3i; and 39 are carried,respectively, by the arms db and ll. The girth-grading movements arecommunicated to the arm at by a lever 58 (Fig. 5) as in the latheillustrated in the aforesaid Patent No. 2,072,228. This lever isslidably mounted on a rockshaft at and a parallel bar 50 affixedthereto. The rockshaft is ournaled in bearings in the frame i l. Theloaded end of the arm ii is sup-.

ported and guided by a radius link d8 just as that of the arm dti issupported and guided by the lever The link t? is carried by the carriageii and connected thereto by a pivot-pin 49. I

In Fig. 2 the cutter-carriage it and the modelwheel carriage it stand intheir initial locations, widely separated, to be driven toward eachother by the screw-shaft H as a turning operation progresses. A nut 51(Fig. l) anchored to the underside of the carriage l0 cooperates withthe left-hand thread of the screw-shaft, while a corresponding nut 52(Fig. 5) having swivel connection with the carriage H cooperates withthe right-hand thread of that shaft. The swivel connection provides forrelatively slow automatic turning of the nut 52 for whateverlength-grading may be called for. An adjustable track 53 (Fig. 2)pivotally connected to the frame is determines the extent to which thenut 52 will be turned, if at all, and since this length-gradingmechanism is like that illustrated in the aforesaid Patent No.2,072,228, no further description thereof is needed here.

A gear 5% (Figs. 3a and l) is affixed to the screw-shaft it between itsscrew portions, and rotation thereof is cl=rived from a shaft 55 locatedat the left-hand end of the lathe. The shaft 55 extends from front torear and is journaled in bearings in the main frame id. The connectionsfor driving the screW-shaftinclude a worm 50 and gear 5?, a shaft 53,spiral gears 59 and til, a shaft 6i, and a worm 02, the latter being inmesh with the gear 5%. The shaft Si is journaled in a cradle @3, asheretofore, and the latter is hung on the shaft 53 about which it may berocked to disen age the worm $2 from the gear 55. at the conclusion of aturning operation.

The shaft 55 (Figs. 3 and 4) also carries bevel gears and the former fordriving a gear train 56 carried by the master swing frame it, and thelatter for driving a corresponding gear train 5? carried by the pilotswing frame 3%. The gear train 0E5 includes a bevel gear 68 and a spurgear rigidly related to each other and both mounted on a cylindricalportion of the rockshaft 35 about which they may rotate without turningthe latter. Likewise, the gear train El includes a bevel gear l0 and aspur gear H, rigidly related and rotatably mounted on a cylindricalportion of the rockshaft 38. The gear train 66 is located at theleft-hand end of the swing frame it, but two corresponding gear trains(not shown) are also carried by this swing frame, one at its right-handend and the other about midway between its ends where one of the gears,M (Fig. 15), is affixed to the spindle that'carries the face plates l9and 23. The three gear trains carried by the swing frame it are allconnected by a common transmission shaft '13 (Fig. 3), as heretofore.

In like manner, the pilot swing frame 3%] carries a gear trainrepresented by the gear l t (Fig-15) for driving the face plate 3 3. Thetrains 6? and M are connected by a transmission shaft l5 (Figs. 2 and3). When the shaft 5:55 is in rotation the three face plates i9, 22 and25 3 will all be driven at equal speeds, but the direction of rotationof the pilot model 3i will be the reverse of that of the master model 27and the work-block 25. Furthermore, considering the angular relation ofeach model to its points of contact with its model-wheel, the models areout of angular phase with each other, the pilot model being slightlyahead of the master model in this respect. The extent of priority of thepilot model is optional, within an undetermined limit, but a phasedifferential of ten degrees is satisfactory for turning lasts. The phasedifferential is one of the fundamentals on which the present inventionis predicated. By way of explaining the effect of such a differential,it is pointed out that all motions of the master swing frame it areanticipated by corresponding motions of the pilot swing frame s0, andthat the earlier motions of the latter are utilized to increase ordecrease, as the case may be, the turning speed of all the face platessimultaneously and equally. The motions of the master swing frame arealso utilized for the same purpose, but they are integrated with thoseof the pilot swing frame to provide composite effects in the matter ofspeed regulation.

The source of rotation for driving the shaft 55 is a variable-speedmotor it (Fig. 3) which, for technical reasons, may be a hydrodynamicunit of the type set forth in the aforesaid Ferris Patents Nos.2,074,068 and 2,105,454. This unit derives its power from an electricmotor ll of the constant speed type, and its regulation of driving speedfrom an adjustable oscillatory regulator '78. A spring 79 connected tothe arm of the regulator normally pulls the arm down to increase thedriving speed, but its force is opposed by a vertically movable rod esalso connected to the arm. A driving pulley 8! on the shaft of the unit76, and a pulley 82 on a countershaft 83 are connected by belts 8'2. 85'transmits rotation from the shaft 83 to the driving member 86 of atoothed clutch the driven member ill of which is affixcd to the shaft55. The driving member 85 may be shifted axially on the shaft 55 toengage and disengage the member 8'? as heretofore, but the presentinvention is not concerned with starting and stopping the operation ofthe lathe. It is concerned with automatic regulation of the turningspeed of the models and a work-block through the medium of controls yetto be described.

Control integrator A train of gears Mei-Jed in'a'fte'rdescribed,receives components of speedregulating movement from three individuallymovable pendular links 95', 92 and 93 on which it is suspended withball-and-socket connections that enable it to rock in all directions.These connections are located in triangular relation (Fig. 11a), and thetriangular area defined by them is provided with many holes 94 in anyone of which a socket member 95 may be attached. The member 35 and theupper end of the rod 80 form another call-and-socket connection forshifting the speed-regulator to and fro.

When the lathe is in operation, outward movements of the pilot swingframe raise the pendular link 9|, and inward movements lower it, withcorresponding components of rocking movement of the integrator 93.Although these components may be compounded with other componentsderived from the links 92 and 93, the purpose of the link 9! is toretard the driving speed of the unit it as the effective radius of thepilot model 3! (reckoned from its turning axis) grows longer, andincrease the driving speed as that eifective radius grows shorter. Itfollows that the turning speed of both models and the work-block will beretarded or increased simultaneously, as the case may be, since theirangular coordination is maintained by the interconnection of theirtransmission gearing. Furthermore, the relative or proportional kineticvalue of these components may be varied by adjusting the socket member55 toward or from the point where the rod 9! and the integrator areconnected.

The linkage about to be described is provided to raise and lower thelink 9!: an arm 98 (Figs. 1, 2, 4, l2 and 13) is fastened to therockshaft 38 of the pilot swing frame, and a bell-crank 97 is looselymounted on a trunnion 38 that supports one end of the master swingframe. This trunnion is fixed in the main frame It. A link 98 connectsthe arm 96 and the bell-crank to oscillate the latter in timed relationto the movements of the pilot swing frame. A ball-end stud 85 carried bythe bell-crank (Figs 8 and 12) has operative connection with a socket atthe upper end of the link Si. It is to be understood that the linkagejust described receives no motion from any source other than the spring4-!) (Fig.

l) and the pilot swing frame, and that the speedregulating componentscommunicated thereby to the integrator 9e anticipate all movements ofthe master swing frame by an interval corresponding to the phasedifferential between the two swing frames.

The ball-end stud 95 has a cylindrical portion on which a differentiallever l 06 is mounted. One end of this lever has sliding connection witha stud lill carried by an arm 32 of the master swing frame.Consequently, the differential lever is carried by two fulcrum studs oneof which (59) moves up and down in synchronisrn with the earliermovements of the pilot swing frame, and the other of which (sea moves upand down in synchronism with th later movements of the master swingframe. The lever let is therefore operated conjointly by both swingframes according to their phase difierential. The operating or outputend of this lever and a rod its suspended therefrom are connected by apivot pin Hi l the center of which travels up and down in arcs tangentto the axis of the master swing frame. Furthermore, the elements are soorganized that the center of the pin I04 will registers with the axislast mentioned whenever theturnin'g axes ofthe two modelsareequidistant' from the respective model wheels, however great: thedistance may be. In operation, the output end of the differential leverwill move up and down according to the difference in radial lengthbetween the contact points: on the models and the respective turningaxes. At some stages these up-and-down movements may be rapid, and atother stagesthey may be slow. Atsomestages the pin I04 may vibrate aboveits median level without moving below the latter, at other stages it mayvibrate below that level without. rising above it, and at still other itmay vibrate between points above and below that level, but,

. wherever it may be, it will not remain at one point for anyappreciable period of time.

The foregoing discussion of the behavior of the differential lever isintended to prepare the way for descriptions of two hydraulic modifiersboth activated by that lever to furnish components of speed-regulatingmovement to the integrator 90 and thereby modify the kineti output ofthe latter according to the contour characteristics of both models. Oneof these modifiers raises and lowers the pendular link 92 (Fig. 11) withasustaining effect to prevent excessive velocity of the swing frames byreducing the turning speed of the models when steep acclivities anddeclivities of contour are in contact with the model wheels. The othermodifier enables sudden surges, slackenings and reversals of the pilotswing frame to raise the pendular link 93 with a transitory effect ofcomparatively short duration and thereby furnish special components ofspeed reduction whenever, surges, slackenings and reversals of theheavier and less sensitive master swing frame are about to occur.

Hydraulic modifiers The rod H33 (Figs. 8, 9, 11, 12 and 14) transmits upand down motions from the differential lever Hill to an arm Hi5 afiixedto a rockshaft me journal-ed in bearings in a casing lfll. Anotherrcckshaft 108 is likewise journaled and is parallel with the shaft H16and spaced therefrom. Both hydraulic modifiers are located between theserockshafts. Two forked arms I09 afi'ixed to one of the rockshafts carrya pivot pin H0, and two similar arms H39 afiixed to the other rockshaftcarry another pivot pin H0. These pins are connected bya tie-rod HI thatmaintains a constant distance between them and transmits motion from oneto the other. Each pin HQ carries two similar pressing pads H2 and 25,the two pads H2 facing each other to operate the sustaining modifier,and the two pads I25 facing each other to operate the transitorymodifier.

Sustaining modifier The sustaining modifier comprises two opposedhydraulic pulsators H3 and H4 (Fig. 9) each a normally expandingbellows, a large duct I l-5 in a fixture connecting their inner ends, acylinder 1 l6 adjoining the duct, and a ram l I! movable up and down inthe cylinder. The chamber formed by these elements is filled withliquid, but the latter is not indicated in the drawings. The upper endof the ram engages and supports an arm H8 affixed to a rockshaft H9provided with an arm I28 (Fig. 11) from which the link 92 is suspended.One input point of the integrator 30 is thus supported by a column ofliquid in the cylinder I I6. Each-bellows is contained in a fixed cageI2 I, and the outer end of each cage is open and provided with a lip I22which serves as a stop to arrest the back strokes of the end wall I23 ofthe corresponding bellows. The pads H2 are adapted to enter the cagesI2! to compress the respective bellows one at a time, but never both atonce because the distance between the confronting faces of the pads isjust equal to the greatest distance between the outer faces of the wallsI23. Fig. 9 represents a typical relation in which the bellows M3 ispartially compressed by the pad abutting its left end, while theopposite pad is retracted from the right end of the bellows H4 whichabuts its arresting lip I22. The ram II! is raised above its normalposition in consequence of compressing the bellows H3, but the sameeffect would be produced by compressing the bellows I It to an equalextent.

It may now be understood that the ram II? will stand at its lowestposition only when both bellows are distended as far as their arrestinglips I22 will permit, and that this position corresponds to the neutralor median position of the assemblage comprising the pads I I2 and thetierod III. It is also to be understood that the neutral position of thepad assemblage corresponds to any position of the differential lever I(Fig. 13) that locates the center of the pin I04 in coincidence with theaxis of the master swing frame. Any upward movement of the pin I04 abovethat axis will compress the bellows I It, and any downward movementbelow that axis will compress the bellows I I I. In another sense, thelast statement means that the sustaining modifier will maintain avariable component of speed reduction whenever the swing frames areunequally displaced by acclivities and declivities of the models, butnot when the turning axes of the two models are equidistant from therespective model-wheels, and that the magnitude of this component willvary as the inequality of such displacement varies. Extending thisanalysis further, the steeper acclivities and declivities in thesurfaces of the models will produce greater components of speedreduction than the less steep ones will produce, since the modifier isoperable conjointly by both swing frames according to their phasedifferential.

Transitory modifier This modifier comprises two opposed hydraulicpulsators I26 and IZl of equal capacity (Fig. 12) each a normallyexpanding bellows, a restricted duct I28 in a fixture connecting theirinner ends, two cylinders I29 and I39 communicating with the duct, twovertically movable rams ISI and I32, one in each cylinder, and aneedle-valve I33 arranged to regulate the flow of liquid to and frobetween the cylinders. The chamber formed by these elements is filledwith liquid, but the latter is not indicated in the drawing. Unlike thesustaining modifier, no stops are provided to arrest the back strokes ofthe outer ends of the bellows I and I21, and the latter therefore remainagainst the respective pads I25 under all conditions of operation. Bothrams ISI and I32 are arranged to support an arm its when the liquid isin equilibrium. This arm is fastened to a rockshaft I35 provided with anarm I36 from which the link 93 is suspended to support one input pointof the integrator 95.

In operation, any upward motion of the rod ItIZi derived from thedifferential lever Hit will compress the bellows I26 and permit acommensurate expansion of the bellows I21. If the quantity of liquidthus displaced exceeds the relief afforded by the needle-valve I33 thesurge produced by the bellows I26 will drive the ram I3I upward, with acorresponding component of speed-reducing movement of the integrator 90,but the efiect thus produced will be transitory because the flow ofliquid past the needle-valve will tend always to restore equilibrium ofthe liquid in both bellows and both cylinders I29, I30. In like manner,any downward motion of the rod IE3 will compress the bellows I27 andrelieve the bellows I26, and the effect on the integrator will be thesame as that described above, but in this case the ram I32, instead ofthe ram I3l, will be the one to furnish a transitory component ofspeed-reducing movement to the integrator. The speed-reducing componentsproduced by the transitory modifier occur whenever a surge of the pilotswing frame in either direction is'so great or sudden as to overload therelief afforded by the needle-valve I33, and these components, if theneedle-valve be correctly adjusted, begin to lose their effectimmediately upon reaching their peak. Nevertheless, their effect may beprolonged sufficiently by the needle-valve to prevent too rapid turningof the master model at those stages when inertia of the master swingframe might otherwise cause separation of the master model and itsmodel-wheel.

The magnitude of these components may be regulated independently oftheir periods of duration by shifting the output socket member 95 (Fig.11a) toward or away from the input link 93, and, in like manner, themagnitude of the speed-reducing components derived from the sustainingmodifier may be regulated by shifting the same socket member toward oraway from the input link 92.

Now, supposing that Fig. 16 represents the cross-sectional contour of aforepart model in a plane intersecting the cone portion thereof, andthat this model is set up in the pilot swing frame while its mate is setup in the master swing frame, the pilot model will rotatecounterclockwise about its turning axis, represented by a dot ac, andthereby bring the points a, b, c, d and e of this contour successivelyinto contact with the pilot model-wheel. The corresponding points on themaster model will be brought into contact with its model-wheel laterthan those of the pilot model by an interval constituting the phasedifferential which may be considered as 10.

Following the point of contact as it would progress in a clockwisedirection with respect to the pilot model, and considering point a as astarting point for no reason except that the radial dimension of themodel is shortest at this point, the pilot swing frame will swing outfrom a to 12, thereby furnishing speed-reducing components to theintegrator 9e (Fig. 11a) by raising the input link 95. During the sameperiod the acclivity of the model contours will cause collapsing of thebellows MS (Fig. 9). Consequently, the sustaining modifier will furnishadditional speed-reducing components to the integrator by raising theinput link 92. Although the steepness of the acclivity increases from ato b, the increase is gradual and may not produce much, if any,speed-reducing action on the part of the transitory modifier (Fig. 11.).However, if any such action does occur, it will not begin until point I)of the pilot model has nearly reached the point of contact.

As point b of the pilot model is leaving, and point I) of the mastermodel is approaching, the

point .of contact, the differential lever Ito (Figs. 1 and 13) will berocked suddenly the clockwise direction, partly by downward movement ofthe fulcrum stud 5.9 and partly by upward movement of the fulcrum studIBI. At this stage the integrator 90 will reecive speed-reducing components from the bellows II 4 of the sustaining modifier, and additionalspeed-reducing components from the bellows I21 of the transitorymodifier The latter components will cease when point I; .of the mastermodel passes the point of contact.

:Since the effective radial length of the models growsshorter from b toc, the input link 9| of the integrator will furnish speed-increasingcomponents, but these will be partially, if not wholly, counteracted byspeed-reducing components due to the declivity and the correspondingaction of the sustaining modifier (bellows H4) and the input link 92.

The acclivity from c to d (Fig. 16) is not steep near point but is verysteep near point (1, and the speed-reducing effect of the sustaining modifier (bellows H3) will be developed accordingly. At the same time, thespeed-reducing effect of the radius control (input link 9|) will notonly be increased but will be added to that of the sustaining modifier.If these two controls do not retard the turning speed enough to maintainequilibrium of the liquid in the transitory modifier the bellows I 26will raise the ram I3I and the input link .93, thereby retarding thespeed still more.

As the point of contact on the pilot model advances from d to e, theoutswing of the pilot swing frame will cease abruptly and the backswingthereof will begin abruptly, but since the inertia factor of the masterswing frame is much greater than that of the pilot swing frame, themaster swing frame requires greatly reduced turning speed until it, too,has passed the critical stage corresponding to the run from d to e onthemaster model. The radius control will undergo only an in ignificantchange during this stage, but thetransitory modifier (bellows I21) willreceive a great surge from the differential lever Ill!) as the fulcrumstud 99 drops while the stud :IUI continues to rise. Consequently, theinput link 93 will rise with great speed-reducing effect. The samerocking motion of the differential lever IBB will transfer thespeed-reducing eifect of the sustaining modifier from the bellows H3 tothe bellows H4, but the period of transition will be so short thatlittle, if any change of speed will be derived from that modifier.

As the efiect of the transitory modifier subsides .at or near point e,the effect of the sustaining modifier will increase with the steepnessof the declivit-y, but beyond that point the diminishing radius of thepilot model will lower the input link .94 of the integrator while, atthe same time, the diminishing steepness of the declivities of bothmodels will lower the input link 92. Consequently, the turning speedwill receive accelerative components from two controls (radius controland sustaining modifier) from point e to point a.

A recapitulation of the three automatic speedregulating controls couldbe reduced to the following terms; viz., the radius control is notaffected by the phase differential, but utilizes only the outswing ofthe pilot swing frame to furnish speed-reducing components, andback-swing of that same swing frame to furnish speed-increasingcomponents. The sustaining modifier requires phase differential of twomodels and two swing frames and is operated conjointly by both swingframes according to their differential The effect of this modifiervaries according to the steepness of acclrvities and declivities. Thetransitory modifier requires the phase differential of two swing framesto enable sudden or abrupt surges and reversals of the pilot swing frameto moderate the corresponding sur es and reversals of the master swingframe. The motions of the radius control may be rendered ineffective byplaciugthesocket member '95 (Fig. 11a) on a line intersecting the inputlinks 92 and 53; those of the sustaining modifier may be renderedinefiective by placing that socket member on a line intersecting theinput links 9i and and those of the transitory modifier may be renderedineffective by placing the socket member on a line intersecting theinput links SI and 92.

Although the'link-age for imparting girth-grading movements to themodel-wheel is the same as the corresponding linkage shown in theaforesaid Patent No. 2,072,228, a brief description thereof now follows.A rocker M (Figs. 4, .6, 7 and 8) affixed to the rockshaft 35, andconstituting a part of the master swing frame, carries two trunnionsI4], I42, lying on a common axis, but the confronting ends of thetrunnions are spaced to clear elements located between them. A pair oflinks I 43 mounted one on each trunnion are connected by a pivot pin I44which extends through a link I45. The latter connects the pin I M and anarm I46 affixed to the rockshaft '49 (Fig. 5) from which themodel-wheels derive their grading motion. The distance between the axisof the pin I44 and that of the trunnions is exactly equal to thatbetween the axis of the rockshaft 35 and the axis of the trunnions. Thepin I 44 may therefore be placed above, below or in alinement with theaxis of the rockshaft 35. In the latter relation the pin I44 and therockshaft 49 will remain stationary while the master swing frame is inmotion, and the girth-grading ratio will be 1 to .1. Grading up requiresplacing the pin I44 below, and grading down requires placing the pinabove the axis of the rockshaft 35. For this purpose the lathe isprovided with manually operable adjusting means including a crank I47(Figs. 1, 2 and 12), a rotatable shaft I48, gearing (not shown herein),and a link I49 (Fig. 6) connecting the gearing and the pin I44. Thislink may be adjusted by the crank I 47 to shift the pin I44 up and downto any selected grading position The link I50 (Figs. '7 and 8) and thearm I5I are provided to facilitate assembling the rockshaft 35 and therocker I40 in the main frame I4, and to tie them in a constant angularrela tion. The arm I 5| is pinned to the rockshaft, while the link I50is mounted on the trunnion I4 I. When the link and the arm I5I areconnected by a screw 552 the rocker I40 becomes, in effect, a part .ofthe master swing frame.

Having described our invention, what we claim as new and desire tosecure by Letters Patent of the United States is:

'1. A copying lathe comprising, a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being less than 90 out of angular phase with each other as betweenthe two models, an adjustable regulator connected to said driving unitfor varying the driving speed thereof, and movable linkage connectingthe regulator and the pilot swing frame whereby swing of the latter istransmitted to the regulator for shifting the same to and fro.

2. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being less than 90 out of angular phase with each other as betweenthe two models, an adjustable regulator connected to said driving unitfor varying the driving speed thereof, a differential member, meansconnecting one point of the differential member to the master swingframe and means connecting another point of the differential member tothe pilot swing frame, and a member engageable with the regulater andconnected to a third point of said differential member for shifting saidregulator.

' 3. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a wora block, mastermodel-wheel, an individually movable pilot swing frame. rotatable meansiournaled in the latter for carrying a pilot model, a pilot model .el, avariable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being less than 95 out of angular phase with each other as betweenthe two models, an adjustable regulator connected to the driving unitfor varying the dr ving speed thereof, means for motion of the pilotswing frame to said regulator, a movable member interposed in the motiontrans-- mitting means for modifying the effects of said motiontransmitting means on the regulator, said modifying member displaceableconjointly by both of the swing frames according to thei phasedifferential.

4. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being less than 90 out of angular phase with each other as betweenthe two models, an adjustable regulator connected to the driving unitfor varying the driv ing speed thereof, differential means operablyconnected to both swing frames for movement thereby, and meansconnecting said differential means to said regulator.

5. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit,

transmission means operable by said unit for driving both of saidrotatable means at equal speeds, said rotatable means being out ofangular phase with each other as between the two models, an adjustableregulator connected to the driving unit for varying the driving speedthereof, a kinetic integrator for shifting the regulator to and fro,means connecting the pilot swing frame and one point of said integratorfor moving that point to and from in synchronism with the movements ofthat swing frame, and modifying means connected to another point of theintegrator for moving that point with speed-regulating components, saidmodifying means being connected to both of the swing frames to beactuated by them conjointly according to their phase differential.

6. A. copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds,said'r'otatable means being out of angular phase with each other asbetween the two models, an adjustable regulator connected to saiddriving unit for varying the driving speed thereof, an angularly movableintegrator having three points of suspension in triangular relation,means effectively connecting an output point of said integrator and thespeed-regulator, displaceable members connected to and actuated by thepilot swing frame alone for furnishing speed-regulating componentsthereof to one of said three points of the integrator, a sustainingmodifier, means connecting said sustaining modifier to another one ofsaid three points for furnishing sustained speed-regulating componentsthereto, a transitory modifier, means connecting said transitorymodifier to the third one of said three points for furnishing transitoryspeed-regulating components, and differential means for operatingboth ofsaid modifiers at once, said differential means including membersmovably connecting the swing frames with both modifiers and actuated byboth swing frames conjointly according to their phase differential.

'7. A copying lathe comprising a master swing frame, rotatable meansiournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable 'pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-Wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being out of angular phase with each other as between the twomodels, an adjustable regulator connected to said driving unit forvarying the driving speed there f, an .angularly movable integrator,means includ' member effectively connecting an output point of saidintegrator and the speed-regulator, movable members ccnnecting the pilotswing frame and the integrator and actuated by the pilot swing framealone for furnishing sustained speed-regulating components to one inputpoint of said integrator according to radial variations of the pilotmodel, a sustaining modifier, means connecting said sustaining modifierto another input point'of said integrator for fllll iingsustainedspeed-regulating components, and a dif- 15 ferential leverhaving connections with said modifier, and means for operating saiddifferential lever by both of said swing frames conjointly according totheir phase differential.

8. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit, transmission means operable by said unitfor driving bothof said rotatable means at equal speeds, said rotatablemeans being out of angular phase with each other as between the twomodels, an adjustable regulator connected to said driving unit forvarying the driving speed thereof, an angularly movable integrator, amember efiectively connecting an output point of said integrator and thespeed-regulator, members connecting the pilot swing frameand theintegrator and actuated by the pilot swing frame alone for furnishingsustained speed-regulating components to one input point of saidintegrator according to radial variations of the pilot model, ahydraulic modifier means connecting said hydraulic modifier to anotherinput point of said integrator for furnishing transitoryspeed-regulating components, and differential means for operating saidmodifier, said differential means being connected to and actuated byboth of said swing frames conjointly according to their phasedifferential.

9. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled in the latter for carrying a pilot model, a pilot model-wheel,a variable-speed driving unit, transmission means operable by said unitfor driving both of said rotatable means at equal speeds, said rotatablemeans being less than 90 out of angular phase with each other as betweenthe two models, an adjustable regulator connected to said driving unitfor varying the driving speed thereof, a differential member operativelyconnected to said swing frames for movements according to their phasedifferential, and mechanism activated by resultant pivotal movement of aportion of said differential member for shifting the regulator.

10. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a

master model-wheel, an individually movable pilot swing frame, rotatablemeans journaled in the latter for carrying a pilot model, a pilotmodel-wheel, a variable-speed driving unit, transmission means operableby said unit for driving both of said rotatable means at equal speeds,said rotatable means being out of angular phase with each other asbetween the two models, an adjust able regulator connected to saiddriving unit for varying the driving speed thereof, a differentialmember, means connecting said differential member to both swing framesfor movement according to their phase differential, a plurality ofdissimilar modifiers, means connecting said modifiers to saiddifferential member for movements thereby, a kinetic integrator forshifting the speed regulator, and connections operable by said modifiersrespectively for actuating the integrator, said connections beingconnected to the integrator at separate points of the latter.

11. A copying lathe comprising a master swing iii) frame, rotatablemeans journaled therein for carrying a master model and a work-block, amaster model-wheel, an individually movable pilot swing frame, rotatablemeans journaled in the latter for carrying a pilot model, a pilotmodel-wheel, a variable-speed driving unit, transmission means operableby said unit for driving both of said rotatable means at equal speeds,said rotatable means being less than 90 out of angular phase with eachother as between the two models, an adjustable regulator connected tosaid driving unit for varying the driving speed thereof, a differentiallever operatively connected to said swing frames for movements accordingto their phase differential, a modifier operatively interconnected withthe regulator and said lever for imparting speed-retarding and-accelerating movements to said regulator in accordance with thesteepness of acclivities and declivities in the contours of the models,and a'second modifieroperatively interconnected with the regulator andsaid lever for imparting transitory surges of supplementalspeed-retarding and -accelerating movement to said regulator inaccordance with deviations inthe steepness of such acclivities anddeclivities.

12. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame shorter andlighter than the master swing frame, rotatable means journaled in thepilot swing frame for carrying a pilot model, a pilot model-wheel, avariable-speed driving unit, transmission means operable by said unitfor turning said rotatable means in both swing frames at equal speeds,the rotatable means in the pilot swing frame being less than 90 out ofangular phase with and ahead of the rotatable means in the master swingframe, a regulator connected to the driving unit for varying the drivingspeed thereof, and mechanism including pivotally connected leversoperated by swinging movements of the pilot swing frame alone forshifting the speed-regulator to and fro according to radial variationsin the pilot model.

13. A copying lathe comprising a master swing frame, rotatable meansjournaled therein for carrying a master model and a work-block, a mastermodel-wheel, an individually movable pilot swing frame, rotatable meansjournaled therein for carrying a pilot model, a pilot modelwheel, avariable-speed driving unit, transmission means driven by said unit fordriving both of said rotatable means at equal speeds, the rotatablemeans of the pilot swing frame being less than 90 out of angular phasewith and ahead of that of the master swing frame, a regulator forvarying the driving speed of said unit, a pivotally suspended kineticintegrator actuated in part by movements of the pilot swing frame, meansconnecting said pilot swing frame to said regulator for shifting theregulator to and fro in accordance with radial variations of the pilotmodel, a differential lever, members supporting said lever and connectedto both swing frames, a hydraulic ram arranged to impart speed-retardingimpulses to the integrator, a pair of hydraulic pulsators both engagingthe liquid for operating said ram, interconnected members actuated bysaid differential lever for operating said pulsators alternativelyaccording to whether said lever is in one or the other of two adjoiningdivisions of its operative range, and stops arrangedto arrest the backstrokes of said pulsators 17 at points corresponding to the juncture ofsaid divisions.

LAURENCE E. TOPHAM. CLYDE L. KNOTT.

REFERENCES CITED The following references are of record in the file ofthis patent: I

Number 18 UNITED STATES PATENTS Name Date Topham Apr. 8, '1930 Black eta1 Mar. 31, 1931 Howe Dec. 31, 1935 Turchan June 1'1, 1946 Johnson June24, 1947

